Lake Avernus

Lake Avernus is a small volcanic crater lake in the Campania region of Italy, within the Phlegraean Fields near Pozzuoli and the ancient Greek site of Cumae. It has a long cultural association in Roman literature as an entrance to the underworld.

The rim of the crater and the lake remain a point of interest for visitors because of the compact volcanic landscape and nearby classical archaeology. The lake’s quiet shores are used for short walks and views over the crater.

In Roman times the basin was adapted by engineers and commanders; notably, the area was linked into the harbour system used by Agrippa in the late first century BC so that the lake and neighboring lagoons helped conceal parts of the Roman fleet. Classical authors describe the lake’s mythic associations and its use in antiquity.

Lake Avernus sits within the Phlegraean Fields to the west of Naples, close to Pozzuoli and the ruins of Cumae, in a volcanic coastal plain dotted with craters and tuff-ring lakes.

• Volcanic setting: Located within the Campi Flegrei volcanic area, the lake occupies a volcanic crater and has strong associations in Roman literature as an entrance to the underworld.
• Roman naval works: In the late Republic the lake was incorporated into a concealed naval base project - Portus Julius - when Roman engineers linked coastal lagoons and lake basins to hide a fleet during Agrippa's campaigns.